Long-term results and prognostic factors in resected pancreatic body and tail adenocarcinomas

Prognostic value of margin clearance in total and distal pancreatectomy specimens with pancreatic ductal adenocarcinoma in a Danish population-based nationwide study

BACKGROUND

The prognostic role of resection margin status following total (TP) and distal (DP) pancreatectomy for pancreatic ductal adenocarcinoma (PDAC) is insufficiently evaluated. In Denmark, pancreatic surgery, including the postoperative pathological examination of the resection specimens, is confined to four centres, all reporting to the Danish Pancreatic Cancer Database (DPCD). In this Danish population-based nationwide study on TP and DP for PDAC from 2015-2019, based on data from DPCD, we evaluated whether there is a prognostically relevant minimum margin clearance definition and whether certain margins hold independent prognostic information.

METHODS

Clinical and pathological data were retrieved from DPCD and supplemented by review of pathology reports and re-microscopy, if needed. One of the study pathologists performed all re-microscopy. The prognostic significance of margin status was evaluated by dichotomisation of the TP cohort (n = 101) and the DP cohort (n = 90) into involved and uninvolved groups, using different clearance definitions (0.5 - ≥3.0 mm).

RESULTS

Following TP, direct involvement of the superior mesenteric artery (SMA) margin had independent prognostic value. When using a clearance definition of ≥ 0.5 or ≥ 1.5 mm for SMA, median survival for R0 versus R1 was 19 (95% CI 14-26) versus 10 (95% CI 5-20) months (p = 0.010), and 21 (95% CI 15-30) versus 10 (95% CI 8-19) months (p = 0.011), respectively. Overall margin status was not of significant prognostic importance following neither DP nor TP.

CONCLUSION

In this Danish population-based nationwide study, SMA margin involvement was a significant isolated prognostic factor following TP, whereas combined assessment of all circumferential margins did not hold statistically significant prognostic information. Following DP, resection margin status did not affect survival.

Proposed Modification of the 8th Edition of the AJCC Staging System for Pancreatic Ductal Adenocarcinoma

OBJECTIVE

The aim of this study was to improve the 8th edition (8th) of the American Joint Committee on Cancer (AJCC) staging system for pancreatic ductal adenocarcinoma (PDAC).

BACKGROUND

The new 8th AJCC staging system for PDAC was released in October, 2016, and will be applied in clinical practice in 2018.

METHODS

Two large cohorts were included in this analysis. One consisted of 45,856 PDAC patients in the Surveillance, Epidemiology, and End Results (SEER) database (2004-2014), and the other consisted of 3166 PDAC patients in the Fudan University Shanghai Cancer Center (FUSCC) database (2005-2015).

RESULTS

Using the 8th AJCC staging system, the median overall survival of the patients in the same stage varied widely among the different substages. We proposed a modified staging system based on median OS in which we maintained the T, N, and M definitions, but regrouped the substages. In the SEER cohort, the concordance index was higher for local disease with the modified staging system [0.637; 95% confidence interval (CI) 0.631-0.642] than with the 8th AJCC staging system (0.620, 95% CI 0.615-0.626). Similar findings were also observed in the FUSCC cohort. In addition, we verified the reliability of the modified staging system in an analysis of patients with different examined lymph node counts (≥15 or 1-14).

CONCLUSIONS

The modified 8th AJCC staging system for PDAC proposed in this study provides improvements and may be evaluated for potential adoption in the next edition.

Impact of Changes in the American Joint Committee on Cancer Staging Manual, Eighth Edition, for Pancreatic Ductal Adenocarcinoma

OBJECTIVE

Consistent and reliable tumor staging is a critical factor in determining treatment strategy, selection of patients for adjuvant therapy, and for therapeutic clinical trials. The aim of this study was to evaluate the number and extent of pancreatic ductal adenocarcinoma (PDAC) cases that would have a different pT, pN, and overall stages based on the new eighth edition American Joint Committee on Cancer staging system when compared with the seventh edition.

METHODS

Patients diagnosed with PDAC who underwent pancreaticoduodenectomy, total pancreatectomy, or distal pancreatectomy from 2007 to 2017 were retrospectively reviewed. A total of 340 cases were included.

RESULTS

According to the seventh edition, the vast majority of tumors in our cohort were staged as pT3 tumors (88.2%). Restaging these cases with the new size-based pT system resulted in a more equal distribution among the 3 pT categories, with higher percentage of pT2 cases (55%).

CONCLUSIONS

The newly adopted pT stage protocol for PDAC is clinically relevant, ensures a more equal distribution among different stages, and allows for a significant prognostic stratification. In contrast, the new pN classification (pN1 and pN2) based on the number of positive lymph nodes failed to show survival differences and remains controversial.

Outcomes and prognostic factors of patients with stage IB and IIA pancreatic cancer according to the 8th edition American Joint Committee on Cancer criteria

AIM

To evaluate the changes in the 8^th edition American Joint Committee on Cancer (AJCC) for defining stage IB and IIA pancreatic cancer and identify their prognostic factors.

METHODS

Pancreatic cancer patients were selected from the Surveillance Epidemiology and End Results database (1973-2013). The enrolled patients were divided into IB and IIA groups based on tumor size according to the 8^th edition AJCC criteria. Clinical characteristics, including age, gender, race, tumor size, primary site, and grade were summarized. Univariate and multivariate analyses were performed to explore the prognostic factors of the IB and IIA stages of pancreatic cancer under new criteria.

RESULTS

A total of 1349 pancreatic cancer patients were included. More patients had stage IB rather than stage IIA. Stage IB tumors (54.85%) were mainly located in the head of the pancreas, while stage IIA tumors were more often located in the tail and head of the pancreas (35.21% and 31.75%, respectively). The survival time of stage IB and IIA patients had no significant difference. Univariate and multivariate analyses indicated that the prognostic factors of survival for stage IB and IIA patients were different. For stage IB patients, age and primary site were the independent prognostic factors; for stage IIA patients, age and grade were the independent prognostic factors. The risk of death was lower among patients aged ≤ 65 years than those aged > 65 years.

CONCLUSION

The prognostic factors for stage IB and IIA patients are different, but age is the independent prognostic factor for all patients. The survival time of stage IB and IIA patients has no significant difference.

Pancreatic Ductal Adenocarcinoma is Spread to the Peripancreatic Soft Tissue in the Majority of Resected Cases, Rendering the AJCC T-Stage Protocol (7th Edition) Inapplicable and Insignificant: A Size-Based Staging System (pT1: ≤2, pT2: >2-≤4, pT3: >4 cm) is More Valid and Clinically Relevant

BACKGROUND

Most studies have failed to identify any prognostic value of the current T-stage protocol for pancreatic ductal adenocarcinoma (PDAC) by the American Joint Committee on Cancer and the Union for International Cancer Control unless some grouping was performed.

METHODS

To document the parameters included in this T-stage protocol, 223 consecutive pancreatoduodenectomy specimens with PDAC were processed by a uniform grossing protocol.

RESULTS

Peripancreatic soft tissue (PST) involvement, the main pT3 parameter, was found to be inapplicable and irreproducible due to lack of a true capsule in the pancreas and variability in the amount and distribution of adipose tissue. Furthermore, 91 % of the cases showed carcinoma in the adipose tissue, presumably representing the PST, and thus were classified as pT3. An additional 4.5 % were qualified as pT3 due to extension into adjacent sites. The T-stage defined as such was not found to have any correlation with survival (p = 0.4). A revised T-stage protocol was devised that defined pT1 as 2 cm or smaller, pT2 as >2-4 cm, and pT3 as larger than 4 cm. This revised protocol was tested in 757 consecutive PDACs. The median and 3-year survival rates of this size-based protocol were 26, 18, 13 months, and 40 %, 26 %, 20 %, respectively (p < 0.0001). The association between higher T-stage and shorter survival persisted in N0 cases and in multivariate modeling. Analysis of the Surveillance, Epidemiology, and End Results database also confirmed the survival differences (p < 0.0001).

CONCLUSIONS

This study showed that resected PDACs are already spread to various surfaces of the pancreas, leaving only about 4 % of PDACs to truly qualify as pT1/T2, and that the current T-stage protocol does not have any prognostic correlation. In contrast, as shown previously in many studies, size is an important prognosticator, and a size-based T-stage protocol is more applicable and has prognostic value in PDAC.

Rare long-term survivors of pancreatic adenocarcinoma without curative resection

Long-term outcome data in pancreatic adenocarcinoma are predominantly based on surgical series, as resection is currently considered essential for long-term survival. In contrast, five-year survival in non-resected patients has rarely been reported. In this report, we examined the incidence and natural history of ≥ 5-year survivors with non-resected pancreatic adenocarcinoma. All patients with pancreatic adenocarcinoma who received oncologic therapy alone without surgery at our institution between 1995 and 2009 were identified. Non-resected ≥ 5-year survivors represented 2% (11/544) of all non-resected patients undergoing treatment for pancreatic adenocarcinoma, and 11% (11/98) of ≥ 5-year survivors. Nine patients had localized tumor and 2 metastatic disease at initial diagnosis. Disease progression occurred in 6 patients, and the local tumor bed was the most common site of progression. Six patients suffered from significant morbidities including recurrent cholangitis, second malignancy, malnutrition and bowel perforation. A rare subset of patients with pancreatic cancer achieve long-term survival without resection. Despite prolonged survival, morbidities unrelated to the primary cancer were frequently encountered and a close follow-up is warranted in these patients. Factors such as tumor biology and host immunity may play a key role in disease progression and survival.

Impact of celiac neurolysis on survival in patients with pancreatic cancer

BACKGROUND

Pancreatic cancer (PC) often produces pain that is difficult to control. Celiac neurolysis (CN) is performed with the goal of improving pain control and quality of life while reducing opioid-related side effects.

OBJECTIVE

We aimed to evaluate whether CN provides a survival advantage for PC patients.

DESIGN

Retrospective case-control study.

SETTING

Single tertiary-care referral center.

PATIENTS

Review of a prospectively maintained database identified patients with unresectable PC who underwent CN over a 12-year period. Each patient was matched to 2 control patients with unresectable PC.

INTERVENTION

CN, which included both celiac plexus neurolysis (CPN) and celiac ganglia neurolysis (CGN).

MAIN OUTCOME MEASUREMENTS

Median survival in Kaplan-Meier curves and hazard ratios.

RESULTS

A total of 417 patients underwent CN and were compared with 840 controls with PC. Baseline characteristics were similar except the CN group had greater weight loss and pain requiring opioids. A mean of 16.6 ± 5.8 mL of alcohol was administered. For patients who underwent CN, the median survival from the time of presentation was shorter compared with controls (193 vs 246 days; hazard ratio 1.32; 95% confidence interval, 1.13-1.54). There was no difference in survival with unilateral or bilateral injection. However, EUS-guided CN was associated with longer survival compared with non-EUS approaches, and those who received CPN had longer survival compared with CGN.

LIMITATIONS

Single center, retrospective.

CONCLUSION

Our study suggests that CN is an independent predictor of shortened survival in PC patients. A prospective study is needed to verify the findings and determine whether shortened survival results from CN or from other features such as performance status and tumor-related characteristics. It is also imperative to verify our finding that EUS-guided CN provides a survival advantage over other approaches and whether CPN prolongs survival compared with CGN.